Synthesis of iron oxyhydroxide-coated rice straw (IOC-RS) and its application in arsenic(V) removal from water.

Because of the recognition that arsenic (As) at low concentrations in drinking water causes severe health effects, the technologies of As removal have become increasingly important. In this study, a simplified and effective method was used to immobilize iron oxyhydroxide onto a pretreated naturally occurring rice straw (RS). The modified RS adsorbent was characterized, using scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analyzer, and surface area analyzer.

Development of a novel concept for fate monitoring of biocides in liquid manure and manured soil taking 14C-imazalil as an example.

Biocides are frequently applied in animal houses for veterinary hygiene or pest control. Thus, they may reach liquid manure tanks. Biocides that are not transformed during manure storage enter soil by the application of manure as organic fertilizer.

Congener specific analysis of polychlorinated terphenyls.

In order to identify and to quantify polychlorinated terphenyls (PCT) in environmental matrices, the chromatographic behavior of coplanar and non-coplanar congeners was evaluated. A mixture of 16 single PCT congeners was used for method development. Four of these compounds were synthesized for the first time by SUZUKI-coupling reaction.

Chemical causes of the typical burnt smell after accidental fires.

The components responsible for the typical burnt smell that occurs after accidental fires (e.g. in buildings) were identified.

Risk assessment of polycyclic aromatic hydrocarbons in a Mediterranean semi-enclosed basin affected by human activities (Abu Qir Bay, Egypt).

The contamination of sediments and mussels sampled from Abu Qir Bay by polycyclic aromatic hydrocarbons (PAHs) was investigated. Concentrations of PAHs recorded in the bay sediments ranged from less than MDL to 2660 microg/kg dw. In general, concentrations of PAHs in mussels were higher than their corresponding sediment concentrations reflecting their great bioavailability (242-3880 microg/kg dw).

Increase of platinum group element concentrations in soils and airborne dust in an urban area in Germany.

Since 1993, all new cars sold in the European Union had to be fitted with catalytic converters. Undoubtedly, these measures brought about a great progress concerning traffic emission controls. However, this technology also led to new emissions.

Chemical and biological characterization of non-extractable sulfonamide residues in soil.

For sulfonamides, the formation of non-extractable residues has been identified by laboratory testing as the most relevant concentration determining process in manured soil. Therefore, the present study has been focused on the chemical and biological characterization of non-extractable residues of (14)C-labeled sulfadiazine or sulfamethoxazole. In laboratory batch experiments, the test substances were spiked via standard solution or test slurry to microbially active soil samples.

Assessment of the environmental impact of landfill sites with open combustion located in arid regions by combined chemical and ecotoxicological studies.

Two different waste disposal sites in Jordan were investigated in order to determine the environmental situation in context with waste disposal techniques. One landfill, located at Marka/Amman, had been closed about 25 years ago and covered with soil. Here, the waste had been actively open combusted and openings in the cover, still emitting smoke, indicated that waste was still smoldering inside the landfill's body.

Analytical investigations on a releasing agent application in aluminium diecasting.

Background, Aims And Scope: Releasing agents, applied in the aluminium diecasting process, usually consist of water, oils, waxes, polysiloxanes, as well as of a set of additives like emulsifiers, corrosion inhibitors, and biocides. During spray application and part release, gases and aerosols are emitted into workplace air. The chemical compositions of these emissions are determined by the components of the releasing agents and their reaction products formed during thermal stress of more than 700 degrees C.

Test-plot studies on runoff of sulfonamides from manured soils after sprinkler irrigation.

Three test-plot series have been performed to gather information on runoff of sulfonamides from manured arable and grassland after sprinkler irrigation. To prepare test slurries with defined aged residues, liquid bovine manure was fortified with sulfadiazine, sulfadimidine, and sulfamethoxazole and stored short-term. After test-slurry application, the arable land was treated by soil cultivation before irrigation, and the manured grassland was irrigated directly with 50 mm h(-1) for 2 h.

Investigations on the fate of sulfadiazine in manured soil: laboratory experiments and test plot studies.

The fate of 14C-labeled sulfadiazine (SDZ) in manured soil has been investigated in laboratory test systems. In the first approach, stability of 14C-SDZ in liquid bovine manure has been tested. Only 1% of the initially applied radiotracer was mineralized to 14C-carbon dioxide and 82% were transferred to nonextractable residues within a 102-d incubation period.

Formation of PBDD/F from flame-retarded plastic materials under thermal stress.

Thermal treatment of plastics flame retarded with brominated compounds often lead to the formation of PBDD/F, especially if polybrominated diphenyl ethers are used. By the presence of antimony(III) oxide, water and some other metals, the amounts of PBDD/F increase. Even during the production and recycling processes of plastics, PBDD/F can be found in considerable amounts.

Influence of heavy metals on the formation and the distribution behavior of PAH and PCDD/F during simulated fires.

Combustion experiments were performed with an artificial fire load (polystyrene and quartz powder) in a laboratory scale incinerator in the presence of gaseous HCl to simulate accidental fire conditions. The aim of this investigation was to trace back the alterations of the formation and the distribution behavior of PAH and PCDD/PCDF to the presence of CuO or a mixture of metal oxides (CdO, CuO, Fe(2)O(3), PbO, MoO(3), ZnO). The total amount of the 16 PAH target compounds was reduced by the factor of 5-9 when the mixture of metal oxides was present rather than merely CuO.

Isomer specific synthesis using the Suzuki-coupling. Polychlorinated terphenyls as standards for environmental analysis.

Defined polychlorinated terphenyl (PCT) single congeners as reference standards are the prerequisite for the development of analytical methods for their determination and quantification in the environment. The selective synthesis of PCTs for environmental analytical purposes by application of the Suzuki-coupling reaction is described. Under easily modified standard reaction conditions of this coupling process the PCTs can be obtained by reaction of benzeneboronic acids with dibromobenzenes mostly in good yields, as described by the synthesis of following PCT congeners: p-PCT (3,3("),5,5(")-tetrachloro-, 2,2("),4,4(")-tetrachloro-, 2('),3,3("),5,5(")-pentachloro-); m-PCT (3,3("),5,5(")-tetrachloro-) and o-PCT (3,3("),5,5(")-tetrachloro-).

Thermal formation of PBDD/F from tetrabromobisphenol A--a comparison of polymer linked TBBP A with its additive incorporation in thermoplastics.

For a long period, polybrominated flame retardants are under discussion because of the formation of polybrominated dibenzo-p-dioxins (PBDD)/dibenzofurans (PBDF) (PBDD/F) in case of thermal stress. Concerning polymer linked tetrabromobisphenol A (TBBP A), formation of PBDD/F was commonly presumed to be sterically hindered because of the covalent fixation into the polymer backbone. Combustion experiments with additively incorporated TBBP A compared with its polymer linkage revealed, that this assumption is incorrect and has to be revised.

Distribution behavior of heavy metals investigated in a laboratory-scale incinerator.

The distribution behavior of Pb, Cd, Fe, Cu, Mo and Zn was determined in a laboratory-scale incinerator. Points of interest were the influence of the temperature and combustion atmosphere on the emission rates of those metals, orientating at frequent combustion conditions of accidental fires. The experiments were carried out at 600 degrees C and 800 degrees C in N2, air, N2 + HCl and air + HCl atmospheres.

Use of supercritical fluid extraction in the analysis of pesticides in soil.

The applicability of supercritical fluid extraction (SFE) in pesticide residue analysis in soil was investigated by analysing real soil samples from field experiments. Additionally, radiotracer batch experiments were performed to study the release of non-extractable residues. High repeatability, accuracy and high selectivity were the most important advantages of SFE in residue analysis.

Sorption behavior of prochloraz in different soils.

The sorption behavior of the imidazole fungicide prochloraz [PCZ; N-propyl-N-[2-(2,4,6-trichlorophenoxy)ethyl]imidazole-1-carboxamide] was studied in batch experiments with different soils. The soil organic matter content was found to control the amount sorbed by different soils. K(d) values ranged from 56 +/- 0 to 552 +/- 10 (mean = 221 +/- 5) and K(OC) values from 7273 +/- 0 to 16250 +/- 1300 (mean = 11829 +/- 303).

Release of polychlorinated dibenzo-p-dioxins and dibenzofurans by setting off fireworks.

Selected pyrotechnic articles were set off under laboratory conditions. Residues and vapors of smoke as well as unburnt charges were analyzed for polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and their precursors chlorinated benzenes and phenols. The contamination of the selected products with these organic xenobiotics proved to be very variable.

On the degradability of tetrachloroethene in biologically treated wastes.

Investigation on the degradability of tetrachloroethene was performed using fresh and mechanically-biologically pretreated household waste. The corresponding metabolites were determined and the experimental conditions were characterized by the concentrations of methane, organic acids, sulfate and nitrate as well as by pH and redox potential. Furthermore, sorption studies on the substances in different wastes were carried out.

Surface contamination with PASH, PAH and PCDD/F after fire accidents in private residences.

Surface samples were taken from two private residences after real fire accidents. The goal was, to determine the surface contaminations with polycyclic aromatic sulfur heterocycles (PASH), as representatives of a substance class, not investigated in this context, by now, polycyclic aromatic hydrocarbons (PAH) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). Analytical method for the determination of PASH was developed for the respective matrix.

Comparison of acute toxicity and genotoxic concentrations of single compounds and waste elutriates using the Microtox/Mutatox test system.

The Mutatox test has been developed by Microbics Corp., U.S.

Dependence of genotoxicity of benzo[a]pyrene suspensions in Mutatox test on dissolved concentration and S9 addition.

The Mutatox test is a novel genotoxicity test measuring the ability of a test chemical to restore the luminescent state in dark mutants of Vibrio fischeri. Chemicals can be tested with or without rat hepatic S9 enzymes for metabolic activity, so that promutagenic agents can be detected as well. In the Microbics Mutatox Manual (1993, Microbics Corp.

Pentafluorobenzylation of the fungicide metabolite fenpropimorphic acid for GC/MS investigations of soil samples.

For the determination of fenpropimorphic acid in soil samples, a derivatization step with pentafluorobenzylbromide has been established in order to perform GC/MS with negative chemical ionization. In spite of forming the electrophilic pentafluorobenzyl ester, only the fenpropimophic acid anion was detected. Additional derivatization reactions with diazomethane and 2,2,2-trichloroethanol showed that the formation of this acid anion was depending on the leaving group.